Rebar Build Calc

Rebar Calc is a reinforcement steel calculation tool for concrete foundations, slabs, columns, beams, and grade beams. It is built for self-builders, site engineers, and contractors who need an accurate steel takeoff before ordering material — not an approximation based on area alone, but a full bar layout with laps, stirrups, bends, hooks, and a cut list ready for the steel yard. The application works from the actual geometry of each structural element. It places longitudinal and transverse bars at the specified spacing, accounts for the concrete cover on all faces, calculates lap lengths where bars must be spliced, and adds the developed length of bends and hooks to every stirrup and tie. The result is a complete bar schedule: quantities, individual lengths, total linear metres, and weight by diameter. The cut list function takes those lengths and optimises the cutting pattern against standard bar stock length, minimising offcut waste and producing a list that can be handed directly to a supplier or cutting team. Minimum reinforcement percentage is checked against the cross-sectional area of each element, with a flag where the provided steel falls below the reference threshold.